Reconversion of pulp-laps into thinned stock.



A. CURTIS & A. H. WHITE.

RECONVERSION 0F PULP LABS INTO THINNED STOCK. APPLICATION FILED IULY29. 1910.

Patented May 2,1916;

INVENTOR5.

ATTORNEYJ OF BROOKLYN, NEW

RECONVERSION OF PULP-LAPS INTO THINNED STOCK.

- Specification of Letters Patent.

Application filed July 29, 1910. Serial No. 574,446.

To all whom it may concern:

Be it known that we, ALLEN CURTIS, a citizen of the United States, residing at New York city, New York, and AMBROSE H. WHITE, a citizen of the United States, residing at Brooklyn New York, have in- 'vented certain new and useful Improvements in Reconversion of Pulp-Laps into Thinned Stock; and we dohereby declare the following to be a full, clear, and exact description of the invention, such aswill enable others skilled in the art to which it appertains to make and use the same.

Our invention relates to certain new and useful improvements in the reconversion of pulp laps into thinned stock, in the manufacture of paper from paper pulp, and in particular to the disintegrating and shredding of wood pulp after it has been reduced to the lap form on its removal from the wet press.

In the handling of pulp, in accordance with the procedure at present practised, the sheet of pulp when removed by a wet press, is cut from the press roll and folded into a lap. of about the dimensions 31 by 16" by 3", in which state it contains approximately from 30% to 40% of air-dry stock. These la'ps are either piled in stacks as a reserve supply, or are loaded into cars for shipment. To reduce pulp from the lap form to a form in which it can be used on the paper machines, it is removed either from the stacks or from the cars, is loaded upon wagons or hand trucks, and is taken to the beater room, if it is not frozen, or if it is not dry and hard. If it is frozen, it is necesary to transfer it to a warm room to thaw it out, or to-place it over perforated steam coils and to use steam for the thawing operation. If it is'too dry, it is taken to breakers, where hot water canbe added and where it can be retained in the water for a long time, being subjected to agitation therein until it is softened and finally pulled apart until the individual fibers are entirely separated. The soft pulp, or the frozen pulp after it has been thawed and taken to the beater room, is placed in the beaters by hand, together with the proper proportions of sulfite pulp, clay, alum, etc., to produce the desired grade of paper. This customary procedure for the conversion of laps into thinned stock involves a considerable expenditure of labor, the beating operation is of relatively long duration, and the thinned stock contains a greater or less amount of incompletely beaten lumps or chunks which are rejected by the screens and are a source of loss.

Our invention is designed to take the place of the present procedure and to substitute for it a practically continuous operation, reducing the amount of labor required for the reconversion of the pulp laps into thinned stock, reducing the duration of the beating operation, saving the loss now arising from unbeaten lumps or chunks, and saving the steam otherwise necessary for thawing out frozen pulp. As will hereinafter appear, hard pulp and frozen pulp can both be reduced to very small and umform particles, in accordance with our in fvention, the product being a fluffy mass whose fibers can be readily separated by a beating operation of relatively short duration, combined, if need be, with a jordan for the purpose of effecting a still finer separation.

In the accompanying drawing, Figure 1 illustrates in sectional elevation at suitable form of apparatus for the practice of our invention. Figs. 2 and 3 show details.

In the drawing, A indicates a roller conveyer which carries the laps of pulp continuously, as taken from the stacks or from the cars, to the mouth or hopper a of a disintegrator, consisting of two rolls 6,- b, about 30 in diameter, set with rows of hawk-bill teeth 0. These rolls rotate, by power, in the direction indicated by the Patented May 2, T910.

arrows, one of them rotating at a faster rate than the other; 2'. e., the fast roll I) may.

conveniently rotate at the rate of 100 revolutions per minute, while the slow roll 72' rotates at the rate of say 15% revolutions per minute. The pulp, which enters the disintegrator pass in the form of laps of about the dimensions hereinbefore specified is torn apart by the action of the rolls, the slow roll I) with its rearwardly pointing teeth holding the pulp back, while the other roll, which revolves, in this instance, six and one-half times as fast, tears it into pieces not over six inches square or thereabout. The pulp, after being thus torn apart, drops into a shredder, throughthe passageway d. The shaft e of the shredder is provided with a series of shredder knives or blades f and rotates preferably at the rate of 1000 revolutions per minute in the direction of the arrow. It is provided with an adjustable and removable breaker plate 9, and with screen bars it of say gths of an inch by 2% inches, with intervening spaces of about 1 inch in Width.

The effect of the shredder is to reduce the pulp to a fine fiufiy mass, which drops upon a belt conveyer B. The conveyercarries this fiufi'y mass either to the beaters, into which it can be deflected by suitable guides, or into a mixing tank. If carried into the mixing tank, it can be agitated therein with water, and can then be passed through a jordan for the purpose of separating the individual fibers. If carried into the beaters, water is added, and the operation of beating is continued until the individual fibers are separated. When this point has been reached, the ,beaters are emptied, and the pulp is pumped either to the ground wood screening system, or to the stock tank. When the jordan is used, the pulp passes continuously through the jordan to the ground wood screening system or to the stock tank.

Having thusdescribed our invention, what we claim is:

1. The method of making paper from ,pulp which consists in providing the paper pulp in the form of dry or frozen pulp laps and reducing such laps while in their dry or frozen condition to a fine fiuiiy mass, then working such mass into thin pulp, and thereafter forming paper from such pulp.

2. The method of making paper from paper pulp which consists in providing the paper pulp in the form of dry or frozen pulp laps and tearing and pulling the laps apart while dry into fragments and then shredding such fragments into a fine dry fluffy mass, then working such mass into thin pulp, and thereafter forming paper from such pulp. e

In testimony whereof we affix our signatures, in presence of two witnesses.

' ALLEN CURTIS.

AMBROSE H. WHITE.

Witnesses:

CLINTON V. CAssInY, R. B. SHARP. 

